Abstract: By using a high speed tribo-tester, tribological behaviors of 30CrMnSiNi2A steel were investigated under high speed dry sliding conditions. Morphology of the worn surfaces and the debris were analyzed by scanning electron microscope and the oxides of worn surfaces by friction heat were detected by X-ray diffraction. The results show that friction coefficient declined with increasing load and sliding speed. The sliding speed was the main factor affecting the friction coefficient. At the beginning of friction, the friction coefficient decreased rapidly while the surface temperature of pin dramatically increased. After that, friction coefficient and surface temperature reached a steady value. As the sliding speed and load increased, the wear mechanism tranformed from oxidation wear to delamination, plastic deformation, groove and adhesive wear, and oxides on worn pin surface were FeO at lower slidinng speed and load and Fe₃O₄ and Fe₂O₃ at higher sliding speed and load.